Hydraulic brake hose



oct; 2o, 1942.

E. s. MacPHERsoN HYDRAULIC BRAKE HOSE Filed My 51, 1941 Peienied e1.2o,'1942 HYDRAULIC BRAKE HOSE Earle S. MacPherson, Detroit, Mich., assignor to General Motors Corporation, Detroit, Mich., a

corporation of Delaware Application Mey 31, 1941, serial No. 395,989

2 Claims.

'I'his invention relates to hydraulic brake hose, such hose as is used to connect the brake fluid carrying conduit on a vehicle frame with the braking applyingv motor associated with a wheel.

It is an object of the invention to improve such a hose by adding to its tensile strength.

Another object is the accomplishment of the major object by means which shall be eiiicient, simple and comparatively inexpensive.

' Figure/1 of a drawing shows in plan view the l novel hose assembled on the vehicle.

Figure 2 is a longitudinal section of the hose. Figure 3 is an enlarged end view as seen in lines 3 3 of Figure 2.

'I'he hose ordinarily used gives satisfactory service but under unusual driving conditions it may fail. One such condition is encountered when objects on the ground engage the hose and apply to it a force greater than can be resistedby the vrubber composition of which the hose is manufactured.

In Figure 1 there is shown a vehicle frame 5 carrying the conduit 'I for hydraulic brake iluid.

The uid conduit is connected to a conventional master cylinder, not shown. At 9 there is illustrated a wheel having a brake drum II. The

drum is covered by a backing plate I3. The plate serves as usual as an anchor for brake shoes, not shown, and as the support for a fluid motor, also not shown, for spreading theshoes into contact with the drum. At I is a coupling in conduit 'I and between the coupling and the iiuid otor and connected to both is a hose marked I As is usual this hose is made from heavy reinforced rubber, the tube being marked I9. The rubber hose is suiiiciently strong to resist internal pressure. It carries iittings 2I and 23 at its ends for connection to coupling I5 and the braking applying motor. Each ttings is formed with a sleeve portion 25 cooperating with an internal tubular nipple 21 to grip the rubber hose. Each fitting has a shoulder 29 to engage part of the nipple.

The construction of hose thus far described is substantially conventional. In driving over rough country it may happen that an obstruction such as that marked 3| in Figure 1 contacts the rubber hose. 'I'he tensile strength of the hose may not be sumcient to overcome the force exercised by the obstruction and the hose may fail. Under such circumstances the hydraulic brake system is rendered useless and braking must be accomplished by such as emergency system as the ve- 4-hicle may carry.

To overcome this difliculty the hose of this invention has a iiexible metal cable 33, preferably of spirally wound strands extending through its central passage. This cable is anchored to the two end fittings. Such a strengthening cable is intended to provide the necessary resistance to overcome the force applied thereto by the obstruction. The passageway is now annular in cross section and the dimensions of the rubber tubes and ilttings are chosen so that the area of the annulus is suicient for the purpose. .It

may be substantially the same as the cross-sectional area of the conventional hose with a passageway circular in section. To each end of the cable is secured in any way found convenient a collar 35. Each collar is positioned within the recess 31 at the end of the nipple and may contact the bottom of the recess. To permit the flow of uid around the collar and to and from the rubber hose there may be bored passages 39 as best shown in Figure 3. These borings enlarge the area of the recess around the collar and their lower ends extend beneath the seat upon which the collar is adapted to rest. By this means the flow of iiuid is insured and the hose is enabled to overcome many an obstruction which would otherwise render useless the hydraulic brake system.

I claim:

1. Hydraulic hose including a hollow tube of deformable material having attaching ttings of metal at its ends, each of said fittings comprising an outer tubular element and an inner tubular nipple adapted to be assembled within said outer element, vsaid hollow deformable tube adapted to be clamped between said outer element and nipple the remote ends of said nipples being internally recessed to form shoulders and a exible cable extending through said deformable tubeand havingterminal abutments engaging said shoulders.

2. The invention defined by claim I1 together with eccentric borings in the bases df said re cesses to afford communication between the recesses and the passages through the nipple when the abutments are seated on the shoulders.

EARLE S. MAcPI-IERSON. 

